U114411

Code

VOLVO U — Network/User

Parking Heater Glow Plug. Circuit Short To Ground

Brand: VOLVO

Type: U — Network/User

Views: UK: 24 EN: 35 RU: 20

AI status

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Page language: EN

Causes

Damaged or chafed wiring contacting chassis ground
Corroded or water-damaged connector/terminals at the glow plug or heater unit
One or more glow plug elements internally shorted
Failed parking-heater control module or output transistor
Stuck relay or shorted relay contacts in heater power supply
Previous repair or aftermarket equipment that altered the harness routing or grounding

Symptoms

Parking heater will not run when commanded
DTC U114411 present; possible additional heater-related codes
Fuse for heater circuit may be blown or repeatedly blow
Reduced or no cabin pre-heating from parking heater
Possible battery drain or unusually high current draw when heater commanded
Sometimes visible heat, burning smell, or melted insulation at fault location (in severe cases)

What to check

Read and record stored/active fault codes and freeze frame data with a scan tool
Check battery voltage and state of charge before tests (12–14 V)
Visually inspect harness and connectors for damage, corrosion, melting, or water ingress around the heater and along the harness route
Inspect fuses and relays for the parking heater circuit
Back-probe heater connector while commanding heater on with scan tool or jumper and observe voltage and signal behaviour
Measure continuity between the glow plug control pin and chassis ground with connector disconnected (looking for low resistance indicating a short)

Signal parameters

Supply voltage at heater power feed when heater is commanded: ~11–14 V (battery voltage)
Control output from heater module (when active): may be switched battery or switched ground; expected change from open/high to near battery/ground depending on design
Typical individual glow plug resistance (typical range): ~0.5–5 Ω — consult vehicle-specific spec
Resistance between control output pin (with harness disconnected) and chassis ground: should be very high/OL; values
Current draw per glow plug when active: typically several amps (varies by design); abnormal high current or short to ground will blow fuses

Diagnostic algorithm

Connect a diagnostic scan tool, record U114411 and any related codes, then clear codes and attempt a controlled re-test to reproduce.
Visually inspect the parking heater, harness routing, and all connectors for damage, heat discoloration, or corrosion. Pay attention where harness passes near exhaust, brackets, or edges.
Check fuses and relays for the heater circuit; replace blown fuses only after locating cause of blow.
With the heater connector disconnected, measure resistance between the heater control output pin(s) and chassis ground. A low resistance indicates a short to ground in the harness, connector, or heater.
Measure individual glow plug element resistance to their body/ground per manufacturer procedure. Replace any plug with resistance out of specification or showing a direct short.
Reconnect and command the heater ON while back-probing the control and power pins. Verify expected supply voltage and that the control signal changes as commanded. If voltage is absent or held to ground, isolate upstream (fuse/relay) or downstream (module output).
If a short is present with the heater disconnected, trace the harness using wiring diagrams: disconnect intermediate connectors to localize the short segment; repair or replace damaged wiring/connector.
If harness and connectors are good but output remains shorted, disconnect the heater control module and check output pin for short. If short persists to battery ground only when module connected, suspect faulty module and verify with substitution or bench test.
Repair wiring, replace corroded connectors, replace faulty glow plug(s), relay, or heater module as needed. Use OEM parts and correct routing/clips to avoid future chafing.
After repairs, clear codes, run heater through several cycles, and confirm no return of U114411 and proper heater operation.

Likely causes

Wiring insulation worn where harness passes near exhaust or sharp edge, contacting chassis (most common)
Corroded multi-pin connector at heater/harness allowing water ingress and shorting pins to ground
Individual glow plug element has failed shorted to its body
Internal failure in heater control module output stage (less common)

Fault status

⚠️ Status

Parking heater: Glow plug circuit short to ground detected by control module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours

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